Method of making a plano plate



June 29, 1965 H. s. WICKHAM 3, 91,293 METHOD OF MAKING A PIANO PLATEFiled Feb. 23, 1960 BYEPTYJLOMW HTTOE/Vf) United States Patent PianoPlate Company, Springfield, Ohio, a corporation of Ohio Filed Feb. 23,1960, Ser. No. 10,224 3 Claims. (Cl. 29-529) This invention relates to apiano plate and more particularly to improvements in the upper basebridge section thereof.

The conventional piano plate includes a series of 40 guide pins fixed inits upper base bridge section in positions uniformly inclined at a angleto a vertical to the plate. These guide pins are essential for properpositioning and tensioning of piano strings which pass over the upperbase bridge section. The strings extend from tuning pins at one marginalportion to one end of a piano plate generally at right angles to theupper base bridge section adjacent thereto where they respectively nestat the junction thereof with one of the guide pins therein, in the acuteangle provided by its inclination. From the guide pins the strings aresharply angled to hitch pins at an opposite marginal portion of theplate, offset toward the opposite end thereof. This provides acontainment of the strings at the upper base bridge section whichprevents them from displacement by riding up and over the pins as theyare tensioned to tune a piano. It also maintains the strings in contactwith the upper base bridge section. This enables optimum tuning of apiano to be effected and maintained.

The conventional procedure for applying the noted guide pins isrelatively slow and quite inefiicient. Holes must be drilled in theupper base bridge section to accommodate the pins at a critical angle.Then the pins must be carefully positioned in the holes by hand toinsure that they are fixed at the required angle and with the properdegree of projection from the bridge section. If there is any inaccuracyin the holes or the pins it will be readily seen that it may bedifficult to maintain the strings in a fixed position under establishedtension. This will create tuning problems.

The present invention is directed to a simplification of piano platesand their method of fabrication which obviates the need for the abovementioned guide pins and thereby reduces their cost. It provides a pianoplate having an improved upper base bridge section which facilitateseffective and efiicient positioning of strings which are passedthereover.

The object of the invention is to simplify and improve piano plateswhereby they may be more simply and economically fabricated and moreeiiicient and satisfactory in use.

A further object of the invention is to provide a simplified procedurefor fabricating piano plates whereby to provide improvements in theirbridge section.

An additional object of the invention is to provide improvement in theupper bridge section of piano plates.

Another object of the invention is to provide improvements in pianoplates and their method of fabrication so as to obviate the need for aninvolved application of guide pins to the bridge sections thereof.

A further object of the invention is to provide a piano plate possessingthe advantageous structural features, the inherent meritoriouscharacteristics and the mode of operation herein mentioned.

With the above and other incidental objects in view as will more fullyappear in the specification, the invention intended to be protected byLetters Patent consists of the features of construction, the parts andcombinations thereof, and the mode of operation as hereinafter described or illustrated in the accompanying drawings, or theirequivalents.

3,191,293 Patented June 29, 1965 Referring to the accompanying drawingwherein is shown one but obviously not necessarily the only form ofembodiment of the invention,

FIG. 1 is a plan view of a piano plate embodying the features of theinvention;

FIG. 2 is an enlarged fragmentary cross sectional view of the plate ofFIG. 1 taken on line 22 thereof showing a portion of its upper basebridge section in elevation; and

FIG. 3 is a cross sectional view taken on line 3-3 of FIG. 2.

Like parts are indicated by similar characters of reference throughoutthe several views.

While the invention is particularly described herein with reference tothe upper bass bridge section of a piano plate it should be kept in mindthat it can be advantageously employed with reference to other bridgesections.

A piano plate embodying the present invention has an upper base bridgesection 2 formed integral therewith. The section 2 is in the form of anarrow elongated bead 3 projecting from the upper surface of the plate 1adjacent a marginal portion 7. The head 3 includes a vertical rib-likeprojection 4- at its apex which is coextensive therewith. The projection4 is provided with notches 5, having parallel sides, spacedlongitudinally thereof and uniformly inclined at a 15 angle to avertical to the plate 1. The notches 5 extend inwardly to the head 3 thefull depth of the projection 4.

The plate 1 is provided with tuning pins 6 conventionally positioned toone end thereof on its marginal portion 7 adjacent the upper base bridgesection 2. A series of corresponding hitch pins 8 are alsoconventionally positioned on the plate 1 at its marginal portion 9opposite the portion 7 and offset relative the tuning pins to which theyrelate in a conventional manner.

As shown in the drawings with reference to the upper base bridge section2, piano strings 10 respectively extend from the tuning pins 6substantially at right angles to the head 3 and through the inclinednotches 5 aligned therewith which are provided in the rib-likeprojection 4. From this point the strings are then sharply angled to theappropriate hitch pins 8. As the strings are conventionally tensionedfor tuning purposes, it will be obvious that they will seat firmly tothe bead 3 within the projection 4 integral therewith. The upper basebridge section 2 as provided herein insures a simple accurate stringingof piano strings It with reference thereto and inherently providespositive positioning of the strings in contact with the bead 3 so as toenable optimum tuning conditions for the strings. Employing theinvention features will thus facilitate establishing and maintaining therequired tension on piano strings which pass over the bridge section ofthe piano plate in which they are incorporated.

The illustrated embodiment of the invention can be simply fabricated.The piano plate 1 is initially cast to form the head 3 and the rib-likeprojection 4 integral therewith in a manner and to a degree clearlyobvious from FIG. 3 of the drawings. A fixture is then employed whichrotatably mounts a series of cutting blades oriented to lie in spacedparallel planes uniformly inclined at a 15 angle to a vertical. Thecutting blades so mounted are connected to conventional controls forsimultaneous and joint rotation thereof. The plate 1 and the fixturemounting the cutting blades are so positioned that on relativeadvancement thereof the rotating cutting blades will simultaneouslyengage the projection 4 on the bead 3 to simultaneously cut the parallelsided notches 5 therein. Thus, the piano plate 1 is provided with anupper base bridge section 2 of an improved nature in which criticallyoriented notches are simply and efiiciently effected.

The invention thus provides a piano plate 1 which obviates the need forconventional guide pins in its upper base bridge section as well as theinvolved procedure employed for applying such pins which has beenfollowed for many, many years in the prior art. The improved upper basebridge section provided is of a nature to facilitate the stringing ofthe piano plate and as noted previously enables optimum tuningconditions to result in the piano in which it is employed. Also, a pianoplate in accordance with the invention affords guide means at its upperbase bridge section having increased strength and stability and offeringa better containment and posi tioning of the strings thereon. Of courseother bridge sections can be similarly formed and improved.

It should be noted that only such detail of a piano plate and thefabrication thereof has been disclosed herein as is pertinent toillustration of the present invention.

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeatures of advantage before enumerated as desirable, but Whichobviously is susceptible of modification in its form, proportions,detail construction and arrangement of parts without departing from theprinciple involved or sacrificing any of its advantages.

While in order to comply With the statute the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise but one of several modes of putting the invention into efiect,and the invention is therefore claimed in any of its forms ormodifications within the legitimate and valid scope of the appendedclaims.

Having thus described my invention, I claim:

1'. A method of forming a bridge section on a piano plate, including thesteps of forming integrally with the plate a raised head of longitudinalextent solid in crosssection and convexly curved in a transverse sense,there being an integral rib extending longitudinally of the bead at thetop thereof, and cutting a longitudinal series of transverse stringreceiving slots in said rib to a depth reaching to the convex surface ofsaid bead, said slots a being cut with parallel sides inclined to theaxis of said bead, the bottoms of said slots extending to and providingfor the bearing of a received string directly on said bead.

2. A method of forming a bridge section on a piano plate having firstand second longitudinally spaced apart laterally oifset marginalportions mounting tuning pins and including the steps of formingintegrally with the plate a raised bead in parallel adjacent relation tosaid first marginal portion, said bead being solid in crosssection andhaving an integral relatively raised rib running centrally thereof alongits top, and cutting a longitudinal series of transverse stringreceiving slots in said rib to a depth reaching to the upper surface ofsaid bead, said slots being cut with their sides inclining in adirection opposite to the direction in which the said second marginalportion is offset laterally of the first said marginal portion.

3. A method according to claim 2, characterized in that said slots insaid rib are cut to be aligned with respective tuning pins, stringsextending from said tuning pins to said hitch pins passing through saidslots and being held by the said inclined formations of said slots inthe lower parts thereof.

References Cited by the Examiner UNITED STATES PATENTS 403,743 5/89Durick 84-209 466,346 1/92 Hastings 84-209 677,465 7/01 Norcross.

867,002 9/07 Betz.

878,926 2/08 Ziegler 84-188 1,736,495 11/29 Grad 29-529 1,867,788 7/32Weber 84-188 2,476,151 7/49 Le Jeune 29-529 2,838,834 6/58 Ganine 29-529FOREIGN PATENTS 297,047 3/ 17 Germany.

9,373 5/93 Great Britain.

247,356 2/26 Great Britain.

607,518 9/48 Great Britain.

WHITMORE A. WILTZ, Primary Examiner.

CARL W. ROBINSON, HYLAND BIZOT, Examiners.

1. A METHOD OF FORMING A BRIDGE SECTION ON A PIANO PLATE, INCLUDING THESTEPS OF FORMING INTEGRALLY WITH THE PLATE A RAISED BEAD OF LONGITUDINALEXTENT SOLID IN CROSSSECTION AND CONVEXELY CURVED IN A TRANSVERSE SENSE,THERE BEING AN INTEGRAL RIB EXTENDING LONGITUDINALLY OF THE BEAD AT THETOP THEREOF, AND CUTTING A LONGITUDINAL SERIES OF TRAVERSE STRINGRECEIVING SLOTS IN SAID RIB TO A DEPTH REACHING TO THE CONVEX SURFACE OFSAID BEAD, SAID SLOTS BEING CUT WITH PARALLEL SIDES INCLINED TO THE AXISOF SAID BEAD, THE BOTTOMS OF SAID SLOTS EXTENDING TO AND PROVIDING FORTHE BEARING OF A RECEIVED STRING DIRECTLY ON SAID BEAD.